title: Induction of senescence and identification of differentially expressed genes in tomato in response to monoterpene.
abstract: Monoterpenes, which are among the major components of plant essential oils, are known for their ecological roles as well for pharmaceutical properties. Geraniol, an acyclic monoterpene induces cell cycle arrest and apoptosis/senescence in various cancer cells and plants; however, the genes involved in the process and the underlying molecular mechanisms are not well understood. In this study, we demonstrate that treatment of tomato plants with geraniol results in induction of senescence due to a substantial alteration in transcriptome. We have identified several geraniol-responsive protein encoding genes in tomato using suppression subtractive hybridization (SSH) approach. These genes comprise of various components of signal transduction, cellular metabolism, reactive oxygen species (ROS), ethylene signalling, apoptosis and DNA damage response. Upregulation of NADPH oxidase and antioxidant genes, and increase in ROS level after geraniol treatment point towards the involvement of ROS in geraniol-mediated senescence. The delayed onset of seedling death and induced expression of geraniol-responsive genes in geraniol-treated ethylene receptor mutant (Nr) suggest that geraniol-mediated senescence involves both ethylene dependent and independent pathways. Moreover, expression analysis during tomato ripening revealed that geraniol-responsive genes are also associated with the natural organ senescence process.
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Sumit
authors.initials: S
authors.lastname: Ghosh
authors.forename: Upendra Kumar
authors.initials: UK
authors.lastname: Singh
authors.forename: Vijaykumar S
authors.initials: VS
authors.lastname: Meli
authors.forename: Vinay
authors.initials: V
authors.lastname: Kumar
authors.forename: Anil
authors.initials: A
authors.lastname: Kumar
authors.forename: Mohammad
authors.initials: M
authors.lastname: Irfan
authors.forename: Niranjan
authors.initials: N
authors.lastname: Chakraborty
authors.forename: Subhra
authors.initials: S
authors.lastname: Chakraborty
authors.forename: Asis
authors.initials: A
authors.lastname: Datta
mesh_terms: D000080462:Acyclic Monoterpenes; D002473:Cell Wall / Q000378:metabolism; D003001:Cloning, Molecular; D005030:Ethylenes / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D063990:Gene Ontology; D018551:Solanum lycopersicum / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism*; D015394:Molecular Structure; D019255:NADPH Oxidases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013729:Terpenes / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D059467:Transcriptome / Q000187:drug effects*
chemical_list: D000080462:Acyclic Monoterpenes; D005030:Ethylenes; D017382:Reactive Oxygen Species; D013729:Terpenes; C036216:ethylene; D019255:NADPH Oxidases; C007836:geraniol